The objectives of this core are to assist Boston Obesity Center members by: 1. Preparing human and experimental animal fat cells and preadipocytes and products of these cells including DNA, RNA, protein, and conditioned medium; 2. Providing consultative advice about experimental design and methods involving these cells and products; 3. Teaching investigators and members of their laboratories about the preparation of fat cells, preadiopocytes, and products of these cells from humans and experimental animals; and 4. Supporting the continuing development of the Adipose Tissue Study group fostering collaborative links among investigators in adipocyte biology, and continuing to provide assistance to investigators new to the field.